1. Field of the Invention
The present invention relates to a semiconductor and, more particularly, to a semiconductor device having an E.sup.2 PROM and an EPROM in one chip.
2. Description of the Related Art
In a known conventional one-chip microcomputer, a RAM and a ROM are formed on one chip. In such a one-chip microcomputer having both RAM and ROM mounted on one chip, the RAM is constituted by an SRAM, and the ROM is constituted by an EPROM or the like.
The area per SRAM memory cell, however, is very large. For this reason, if the RAM is constituted by an SRAM, the area occupied by the RAM in one chip is increased, or the storage capacity of the RAM is undesirably decreased.